1. Field of the Invention
This invention relates to mold assemblies used in the foundry arts, and more particularly to a locating core for providing registration of one mold portion with another mold portion.
2. Description of the Prior Art
When portions of a mold are placed together prior to pouring a liquid therein for producing a molded or cast article, some means must be utilized to register the mold portions so that the cast article takes the intended shape. According to one scheme one portion of the mold is provided with a depression having a particular wall shape and the other portion of the mold is provided with a protrusion having substantially the same wall shape, so that when the two mold portions are placed together with the protrusion positioned in the depression the mold cavity portions in the mold sections are properly aligned. The protrusions on the face of the one mold portion are subject to breakage during handling of the mold prior to mold assembly. As a consequence accurate registration of the mold portions is sometimes lost.
In other instances identical depressions have been made in the mold portions having similar patterns and being positioned in the mold portions so that when a core is engaged by matching depressions in the patterns of depressions the mold cavities are properly registered. The only locating core known to be used in the aforedescribed fashion was shaped like a pair of truncated conical sections having bases of the same diameter and being joined at the bases. The depressions in the pattern had walls which were also frusto-conical. The locating function with the described cores was degraded however, because if one of the frusto-conical depressions was too large the locating core would be inserted too far therein preventing full engagement of the other end of the core by the depression in the other mold half and allowing the other mold half to move in two dimension. Alternatively, if one of the conical depressions was too small in diameter a separation resulted between the mold portions, allowing a ridge of cast material (flashing) to build up along the parting line of the mold. Registration between the mold portions suffers in the first instance and the dimensional integrity and clean up requirements necessary for the end cast articles suffer in the second instance.